The names by which Alonissos was known in the past are Ikos, Evonymos, Liodromia, Chiliodromia. Alonissos has always been a passage for sea routes, already since the 9th millennium BC and, perhaps for this reason, it highlighted shipbuilding as the first art of its people, along with pottery.
The history of the island is lost in the Paleolithic era, when it is believed that it formed a single landmass with the other islands of the Sporades and Thessaly. Tradition states that Cretans led by the mythical hero Staphylos made colonies in Peparithos (today's Skopelos) and Iko. This colonization took place in the 16th century BC, during the Minoan sea rule in the Aegean. At this time, the cultivation of olives and vines also begins.
The Minoan colony later acquires a Mycenaean character. The Mycenaean city is located in the current location of Kokkinokastro, on the eastern side of the island. At the end of the Mycenaean era, Achilles' father, Peleus, comes to the island and stays until the end of his life. According to tradition, there was the tomb of Peleus on the island.
In 476 BC the island joins the Athenian Alliance. During the classical era, Ikos must have had two cities (the geographer Skylax in the 5th century BC, calls it 'dipole'). One must have been located at the site of Kokkinokastro, where remains of the wall are preserved to this day, and the other at the site where today's Village or Old Alonissos is built.
At that time the island was famous for the cultivation of the vine and the fine wine, which was exported in amphorae, which bore the inscription IKION on one of the two handles. At this time it seems that the geographical position of the island is very important. This is also confirmed by the number of ancient shipwrecks that have been found in the area. During that period, the island developed a very significant export activity in key points of the then known ancient world, making its products known as far as the Black Sea.
In 190 BC Alonissos is occupied by the Roman fleet.
We have next to no information about the history of Ikou until the capture of Constantinople by the Franks in 1204, when, together with the neighboring islands, it came under the possession of the Franks. In 1207 the Sporades and consequently Alonissos passed as property to the Venetian Gyzi family.
From then on, along with Skopelos and Alonissos, it will be a fiefdom of alternating conquerors. After the occupation of Constantinople by the Turks, in 1453, the islands came under the possession of the Venetians. They remained Venetian until 1538, when the Turkish fleet, under Hayreddin Barbarossa, imposed Turkish rule.
The Turkish yoke lasted until 1830 when Alonissos together with the rest of the islands of the Sporades became part of the new free Greek state.
During the Revolution of 1821 and during the first years of the liberation of the Greek Nation, Greeks from various parts of Greece fled to Alonissos. They, together with the natives of the island, made up the current population of Alonissos.

Source: Municipality of Alonissos
http://www.alonissos.gov.gr/